Here's why:

* Homologous structures are structures in different species that are similar because of common ancestry. They may have different functions, but their underlying structure reflects their shared evolutionary history.

* Distantly related organisms have diverged from a common ancestor a long time ago. Over time, the evolutionary processes of natural selection and genetic drift have led to significant changes in their genomes and phenotypes.

* More closely related organisms have diverged from a common ancestor more recently. Therefore, they have had less time for their genomes and phenotypes to diverge, resulting in more shared homologous structures.

Example:

* A human and a chimpanzee are very closely related and share a high number of homologous structures (e.g., arms, legs, skull bones).

* A human and a fish are distantly related and share fewer homologous structures. While both have a backbone (vertebral column), their limbs have evolved into very different structures (fins in fish, arms and legs in humans).